Hyper-V is Hypervisor-based virtualization technology from Microsoft. It is available both as Windows Server role (starting with Windows Server 2008) and as a free stand-alone product called Microsoft Hyper-V Server.
Following is a list of Hyper-V-related topics in TechNet Wiki.
General information
Hyper-V / hypervisor Concepts
Hyper-V Resources
Hyper-V Books
Troubleshooting
Nice and valuable list of links :-)